Abstract

Black seed (Nigella sativa) is known as a good source of various biologically active compounds which possess antimicrobial properties. One of our objectives was to elaborate methods of obtaining and extracting peptides from plants. In the current study, we discovered some biological effects of thionins from black seed, such as bactericidal and fungicidal effects. Isolation of thionins performed by combining acidic extraction and fractionation with various liquid chromatography methods. The N-terminal amino acid sequences were revealed using automated Edman degradation. The antimicrobial activity of thionins were evaluated by a microdilution broth assay. A fluorescent spectroscopy and an atomic force microscopy allow to investigate the features of mode of action of the thionins. The two novel peptides from black seed (N. sativa L.), a plant endemic to Central Asia. These peptides, named NsW1 and NsW2, have a high affinity with heparin, a polysaccharide glycosaminoglycan. These molecules were indentified as thionins, a well-known family of plant antimicrobial peptides. These thionins effectively inhibit viability of Bacillus subtilus, Staphylococcus aureus and Candida albicans that has been confirmed using a bacteriological and some biophysical techniques. Obtained data indicate that black seed thionins are biologically active molecules that may be considered to be perspective antibacterial agents.

Keywords

Black seed Thionins Antimicrobial activity Atomic force microscopy

Eugene V. Grishin—Deceased on April 8th, 2016.

Electronic supplementary material

The online version of this article (doi:10.1007/s10989-016-9549-1) contains supplementary material, which is available to authorized users.

Notes

Acknowledgments

This work was supported by Russian Scientific Foundation (Grant No. 14-50-00131) (section devoted of “Isolation and srtuctural characterization of the black seed thionins”), Russian foundation of Basic Research (Grant No. 16-34-60217-mol_a_dk) (section devoted of “Antimicrobial and cytotoxic activity of the black seed thionins”) and Stipend of The President of Russian Federation for young scientists (Registration No. SP-943.2015.4, SP- 2093.2015.4). The authors are grateful to Yulia I. Oshchepkova and Dr. Olga N. Veshkurova (both from Laboratory of Protein and Peptide Chemistry A.S. Sadykov Institute of Bioorganic Chemistry Academy of Sciences the Republic of Uzbekistan) for introduced defatted seeds of N. sativa and the initial stages of the seed extract fractionation; Dr. Elena V. Svirshchevskaya (from Laboratory of Cellular Interactions Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry Russians Academy of Science) for cytotoxity assays of the black seed thionins; Prof. G.D. Zasukhina (from Vavilov Institute of General Genetics Russian Academy of Sciences) and Dr. V.F. Mikhailov (from Burnasyan Federal Medical Biophysical Center of FMBA of Russia) for the important suggestions and advices while the manuscript was in progress.